INR self-monitoring is used by patients on long-term and on lifetime anti-coagulation therapy to measure their INR (International Normalized Ratio) levels themselves, rather than at a clinic. People who self-monitor their INR levels use a portable INR monitor as in a clinic. It requires the patient to test a drop of blood, drawn from a finger at scheduled times, and record the INR level measured by a monitor.
Patient self-testing
People on anti-coagulation therapy who are self-testing provide the INR reading they obtain from their monitor to their healthcare professionals at an agreed time, generally by telephone. The healthcare professional decides if any change to the warfarin dose is required and lets the person know what action is needed. A PT/INR meter can be obtained by contacting an Independent Diagnostic Testing Facility (IDTF). They are able to provide patients with all necessary testing equipment and bill the insurance for test results reported.
Patient self-management
People who self-manage adjust their warfarin doses themselves, following training with their healthcare professional. This means that if the INR reading obtained from their monitor is out of the normal therapeutic range, they are able to make an adjustment to their own warfarin dose by themselves.
International Normalized Ratio (INR)
International normalized ratio (INR) which is a derivative of prothrombin time is a measurement of blood coagulation in the circulatory system. Both are used to determine the clotting rate of blood, which can be affected by anticoagulant usage, liver damage and Vitamin K levels. The preferred range of INR levels for a patient on anticoagulation therapy is usually between 2 and 3, but it tends to vary depending on the patient's requirements.
The advantages of self-monitoring
Patients who self-monitor tend to choose this route for the greater control they feel it gives them over their lives and their condition. This helps to reduce the number of visits being made to their anticoagulation clinic for routine appointments to measure their INR levels. This is a lengthy process in comparison to self-testing and management. Results of clinical studies, which have been recognized by the National Patients Safety Authority (NPSA), show that people who self-monitor keep more frequently within their therapeutic range and have fewer complications including clots and bleeding, compared with people who have their INR levels tested only at their anticoagulation clinic.
UK NHS on self-monitoring
Patient self-care is a key initiative in the NHS Plan for a patient-centered health service and an important component in supporting people with long-term conditions. It is seen to provide: Better symptom management Improve feeling of wellbeing Increase in life expectancy Improvement in quality of life with greater independence Improve Immunity Improve Mental wellbeing
Who self-monitoring is suitable for
Self-monitoring may be a suitable option for a variety of people who are on long term anticoagulation therapy and want the convenience of being able to monitor their own INR levels at a time and place of their own choosing (e.g. if travelling abroad either with work or on vacation). They do have continuous support from their healthcare professionals and there are no upper age limits for self-monitoring and parents can take charge for their children. Self-monitoring is ideal if: People want a larger role in managing their condition and treatment Committed to learning how to self-monitor Would get full support from healthcare professionals Find frequent hospital visits for an INR test inconvenient and disruptive
Clinical trials
In the past 5 years, there have been a number of clinical trials to highlight the advantages of self-monitoring, whether self-testing or self-managing. It also gives an indication of what improvements the self-testing and self-management can do to INR levels.
Clinical reports about INR self-monitoring
"Quality of life changed in a positive way. Independence and better organisation of vacation and spare time were most frequently mentioned advantages."
Extract from a study into the impact of self-monitoring on the quality of life of patients under anticoagulation therapy.
"Patient self-testing . . . is an effective method of monitoring oral anticoagulation therapy, providing outcomes at least as good as, and possibly better than, those achieved with an anti-coagulation clinic."
From international consensus guidelines prepared by the International Self-Monitoring Association for Oral Anti-coagulation.